Differential gearing



Jan. 3, 1939. v A. R. SPICACCI 2,142,575

- DIFFERENTIAL GEARING Filed Sept. 29, 1936 s Sheets-Sheet 1 INVENTO Q A TT/L/O R. SP/CACC],

H/s ATTOQNEY.

Jan. 3, 1939. R, 2,142,575

DIFFERENTIAL GEARING Filed Sept. 29, 1936 3 Sheets-Sheet 2 H/s ATTOQNEY.

- smallin PatentedJam3,1939' Y PATENT OFFICE zoom 1) GEARING mo 3. spam Bristol, com, asignor to Gen- .cral Motors Corporation, Detroit. Micln, a corporation of Delaware 4 September so, me, Serial n 103,134 1 cums. (Cl. 14 -312) 'Ihis invention relatu to dtflerentlal gearing and comprisesallofthe fatnresoinoveltv herein disclosed. Due to the use of hettenmateriala.

methods, mountings, etc., ring gears ior diiierentialscanhemadeotsmalldiameterandyetsatisfactorily transmit the high torque required. However, with a reduction in diameter'oi ring 8 11. greater rigidity win the driving pinion mounting is desirable yet it hecomu increasingly 1o. dimc'ult to use the desirable straddle mounting iorthepinionshaftbecauseoflackoi'roombetweentherlnggearandthediiierential cas for therear bearing with hypoid gearing. Hitherto, the

1g enclosing and supporting carrier in the plane of 4 the ring gear has usually been the factor which determines road clearance but with smaller ring gears thevsise of the carrier-in a plane transverselyottheringgearmaybecanethelimitinz' iactorflithehousingopeninxistobecircularl because the axial length or the ldiiierential case has not been d. Hence it is increasinsly desirable to make the diflerential cage compact in thetaxlal direction in order that full advantagemaybetakenoitheincreasedroadclearance made possihlehysmallerringgears'.

An object oi! the invention accordingly is to provide an improved straddle mounting for the pinionshaitoiadiiierential, especiallyincoma binationwitharinsgearoismalldiameter. Anotherobiect is to provide an improved diiierentialcage-odsmallaxiallengthespeciallyincomhination with'a small rlns gear in order that the enclosing diflermtial carrier may be made diameter both lengthwise and trans-. versely. Another object 'is to provide an improveddiii'ermtialcan'ierior supporting'a diflerentialcageandapinionshaihthemountingbeing applicable to spiral-gears or to D thehypoidtvpe. nnotherobiectisto provide an nnproved'diiterentialgearingotthespurgear 'rommmmotom me'senersnyupondevicesottinseharactentheinventionll comilts in the hereinafter described-and'eiahned. Initsaspects,the inventionisnotlimitedtothespeciflc drlwinllinwhieh in Hg. 1 is a horinontal sectionfliview'oi' a ditheingshownindevitton.

Iii-231ml otanothosunbodimportiomotfliemhodiameter at :the ,dii!erentlalo ing in m planes as indicated by the line Fig. 3'is a vertical sectional view on the line 3-.3 oi Hg. 2. M

Fig.4isaverticalsectionalview onthe line 4-4 of Fig. 2. N

Fig. 5 is a sectional view on the line 5-4 of Fig, 70! another embodiment.

Hg. 6 is a perspective view of the differential cage shown in Fig. 5 with the gearsomitted. 10

Pig. '7 is a vertical sectional view on the line of Fig. 5.

Thenumeral Iii in Fig.1 indicates the usual rear axle housing having an opening H around. which is detachably secured a forwardly proiecting carrier I! having a shouldered seat ll for an antifrietion hearing it. The bearing is herein shown as a preloaded, double row, ball hearing whose outer race ring is clamped by a cap "secured to the carrier by bolts 20. -A pinion shaft 22 having a spiral pinion-24 is clamped to the inner race ring, of the bearing and has a' rearwardly projecting pilot stud ll'journalled in a ball bearing 28 whose inner race ring is retained on the stud by a split ring ill and whose 38. The cage in diameter towards its ringsotthehearins'taresupported eless-ground'sleeves ll which are removably sup N 7 I8 and II which to iacilitateaxialremovalrromthepedestaisbr v a suitable pulling .tool. pedestals are slit attherear as indicated t llandprovidedwith' boltholes sothatthesieevescanbeclamped firmbinpositionto'sunilirtthchcarinl; The innerraceringoithebearingllhassirecspace' 'betweenit'andthe edestalllwhereasaspacing' m sleeve o r washer Q or selectedthicknas is inhetweentheinnerraceringoithebearterposed -lngl2andthepedstilll;' 'I'hespocingwasher is selected to locate the ring gear in proper mesh withthe spiral pinion ll audit transmits I duced by this bearing II upon the bearing II.

The differential cage II has a diiferential pin II which is retained in position by a headed locking pin II which passes through it. The head of the pin II is engaged by the ring gear to hold it in a recess of the cage II, the cage having a half-round recess II which interrupts the gear seat II so that the pin can be inserted before the gear is seated. The usual planetary or bevel gears II are journaled on the differential pin II and mesh with bevel gears II which have pro- Jecting hubs II iournalled in openings of internal flanges II of the cage, The gears II are spiined to drive shafts II and II, the shaft II being the longer because of the offsetting of the cage from the pinion shaft. The rear opening ll of the axle II is closed by a cover II which is preferably welded.

From the foregoing, it will be seen that the ring gear II is on the same side of the differential pin II as the pinion II and that the differential ,cage II has been offset from its usual central po- I sition so that, even with a small diameter ring gear, there is ample room between the pinion II and the drive shaft II for the rear straddle hearing II and its supporting projection II. In other words, all of the differential gears and the differential pin II lie well to one side of the'axis of the pinion shaft so that their bulk and that of the cage parts surrounding them is not inter-- v posed between the pinion and the axle. This construction allows ring gears to be made smaller and increases road clearance. The construction of the carrier II is such that both straddle bearsings have a more rigid support because the right hand side of the carrier casting extends substantially straight towards the axle and does not diverge as on the left side. this making for a carrier which is smaller and for a correspondingly smaller opening II in the axle II.

Figs. 2. 3 and 4 illustrate a modification where in the din'erential gearing and pinion mounting is still more compact and provides increased road clearance. Parts III to III inclusive correspond to parts II to II, respectively. of Pig. 1 and need not be described in detail but it is to be noted that the pinion shaft-is below axle level. be seen that this hypoid type of gearing is inapplicable to Fig. 1 because the projection II would interfere with the ring gear or-the cage.

The ring like projection III for supporting the bearing III is at the inner or rear end of the casting III and actually projects into the axle housing III where one sided it becomes a part of the diflerent'ial pedestal III as best shown in Fig. 3. As shown in Figs. 2, 3 and 4, wherein Fig. 3 is a vertical section in the plane of line 3-3 of Fig. 2, the pedestal III is substantially wholly on the diiierential side of the axis of the pinion shaft and above said shaft and it projects rearwardly from the carrier substantially radially of the axle housing. The pedestal is braced by and itself braces the projection III which is below the pedestal and has a portion projecting into the housing beyond the pedestal and on the other side of thepinion shaft from the differential'gear.

ring gear III is of smaller diameter than h 'lnggear II and issecuredby screwbolts IIItoa seat III on a'difleren'tial cage III. this cage "con- 1s taining a spur gear diiicrentisl and comprising side members III (Pig. 4) connecting ring-like end members. The-cage has its opposite ends formed with internal seats III for radial ball bearings III and III which are supported by centerless-ground sleeves III carried in pedestals III and III. The bearing III is preferably in the plane of the ring gear and is on the same side of the pinion shaft as the ring gear and the cage.

The cage is offset axially so that it lies wholly to 1 one side of the pinion bearing III and its support. thus allowing that hearing to be brought in very close to the sleeve III and the pedestal structure III and out of interfering relation with the ring gear. v The placing of the pinion shaft below axle level helps this close approach and in a manner requires it. The pedestals are slit on the top as shown at III in Figs. 3 and 4 and are provided with clamping bolts III to secure the sleeves III. A spacing washer III of selected thickness is interposed between the inner race ring of the bearing land the adjacent pedestal III while the inner race ring of the otherbearing III has a clearance with the pedestal III.

The diiferential cage III is a one-piece casting and hastwo pairs of parallel longitudinal openbut are axially offset or staggered with respectto gears III so that they mesh on one half of their width with a gearJIIA. The gear III has I a hub orprojection I'II journalled in an internal flange III of the cage. The other gear IIIA has a similar hub or projection I'IIA which is Journalled in a spacing washer I IIA which is'seated in the cage against an internal abutment flange I II, the washer I'IIA having a little abutment flange against which the outer race ring of the bearing III seats. The gear- III is splined to a drive shaft III and the gear IIIA is splined to a drive shaft III. The rear opening I II of the axle housing I II is closed by a welded on cover III. From the foregoing, it will be seen that the entire differential cage is at one side of the rear straddle bearing III which is thus brought in close to the drive shafts. The ring gear III is smaller in diameter than the ring gear II of Fig. 1, and the pinion III and its mounting in the carrier III are closer to the axle housing. The diiferential cage III. by virtue of spur gear construction, is smaller in maximum diameter than the cage II and it is also shorter in the axial direction. The opening I I I is smaller than the opening II. All these features result in increased road clearance which depends partly on the diameter of the ring gear and partly on the diameter of the carrier III in the plane of the opening III.

Figs. 5 to 7 illustrate a modification which gives great compactness to the differential mechanism and carrier especially in a direction lengthwise of the axle casing III whose opening III is even smaller than the opening 'III of Pig. 2; The differential cage III is made shorter axially and the bearings III and I are closer together. This is accomplished by taking advantage of the space between the gears III and IIIA-to support one of them. Gear III has a hub or projection III Journailed in a spacing washer III which is seated in the cage between the outer race ring of the bearing I and a pair of abutments I'll (Fig. I) which 7 9,149,016 project inwardly at the sides or the case past the annular face I. Ihe other gear-281A has a hub or projection 2105 which is journalled in an opening 282 of a cross bar 2, which runs across the middle of the cage from side members 286 which connect ring-like end members ill and 289. -At the other side of the gear 20A is a thin spacing washer I! which fits inthe bearing seat I40 between the outer race ring of the bearin I42 and a pair of-spaced abutments 2 (Fig. 6)

on the side members 280.

From the foregoing, it will be apparent that the difierential-cage is shortened in the axial direction, chiefly because the gear 268A is sup- 18 pflrted by a cross bar 2 in the waste space between the gears. Thus the bearing I42 and its supporting sleeve I" can be. more closely approached to the companion bearing and support; th left side of the carrier 2 is nearer to the go pinion shaft resulting in a smaller axle opening 2 and a carrier of smaller diameter at this opening. g

I- claim:

1. In apparatus of the character described, I 35 axle housing, a diiferential cage having a ring gear at one end, a driving pinion having a supporting shaft projecting rearwardly beyond the pinion and into the axle housing, the shaft being I below axle level, the cage being offset with reso spect to the shaft, a carrier secured to the axle housing and having pedestals projecting into the housing, bearings for rotatably supporting the cage from pedestals, one of the bearings being in the plane ofrthe ring gear, and the carrier 35 also-having a projection below axle level and extended into the axle housing beyond the adjacent cage supporting bearing to provide a bearing support for the projecting end of the shaft;v

substantially as described. 40 2. In apparatusof the character described, an

axle. housing, a differential cage having a ringgear, a driving pinion having a supporting shaft projecting into the axle housing. the cage bein offset with respect to the shaft, .a differential 5 carrier secured to the axle-housing and having pedestals projecting into the housing. bearings for rotatably supporting the'cage from the pede-' stals, and'the carrier also having a portion projecting into the axle housing beyond the end of so the cage and its adjacent supporting bearing to provide a bearing support for the projecting end of the shaft; substantially as described.

axle housing, a differential cage having a ring 56 gear, a driving pinion having a supporting shait 'projecting rearwardly beyond the pinion, the entire cage being oifset to one side of the shaft. the shaft and the pinion being below; axle level. a diiferential carrier secured to the axle housin the cage beingoffs'et wholly to one side of the shaft, the pinion shaft proiecting mm the axle 7o and a diflerential carrier secured to the axle housing and having a portion projectingintothe housing beyond the end of the cage'to term a bearingsupport for the shaft; substan-' ,3 tlally'as described.

and having a pedestal projecting into the axle 5. In apparatus of the character described. a one-piece diiferential cage comprising spaced side members connecting a pair of ring-like end members, a differential gear havinga hub journalled in one of the end members, a spacing 5 washer mounted in the other end member and insertable axially therein, and a differential gear coaxial with the first mentioned gear and having its hub journalled. in the spacing washer; substantially as described.

6. In apparatus of the character described, a differential cage comprising spaced side members connecting a pair of end members, a spacing washer fitting in one of the end members, and a cage supporting bearing in said one end memis her and having its outer race ring abutting against the spacing washer; substantially as described.

7-. In apparatus ofthe character described. a diiferential' cage comprising spaced side meming washer fitting in one of the end members,

a differential gear having a hub journalled in the spacing washer, and a cage supporting bearing fitting in said one end member and abutting against the spacing washer; substantially as 8. In apparatus of the character described. a differential cage comprising spaced side members connecting a pair of end members, a cross bar connecting the side members, a difierential gear havin a projection jdurnalled in the cross bar, and a differential gear coaxial with the first mentioned gear I d having a journal support in one of the endmembers; substanflally as described. a

. 9. In apparatus of the character described, a differential cage comprising end members and an intermediate crossbar, a washer fitting in one of the end members, difi'erential gears on 40 opposite sides of the cross bar, one of the gears being journalled in the washer and the other gearbeing journalled in the cross bar; substantially as described.

10. In apparatus of the characterdescribed, a difierentialjcage having a cross bar and a ringlike end member, a washer fitting in the end member, an antifrictlon bearing fitting in the end member and the washer. and a 11. In apparatus of the character described, a

3. In apparatus. the character described. difierential cage having a ring-like end member stantially as described,

12. In.apparatus of the character described, a so difi'erential cage having ring-like end" members, abutments adjacent to the end members. 8910- ingwashers fittingintheendmembersagainst the abu'tments, and antifriction fitting in theend members againstthewashers: as

substantiallyasdescrlbed.

"13.-In apparatus of thecharactdbdesdribei'an axlehousingofthebaniotvpehavinganopening, a differential cage'a'nd a ring gear inthe pen ns.,a d vi p n on havin supno fi sro shaft projecting into the axlehousing. the cage beingofisetwhollytoonesideottheshsfhadifferentialcarriersecuredtotheaxlehousingand. having a pedestal connected thereio and projectingintothcaxlehwsingbeyondtheadja-u centendofthecage.abearingsupportedbythe pedestal to support the adjacent end of the cage, the carrier also having a portion connected thereto and projecting within the axle housing to provide a bearing support for the projecting end oftheshaft,saidbearingsuppcrtbeing beyond the cage supporting bearing and bracing the pedestal while being itself braced by the pedestal; substantially as described.

14. In apparatus of the character described, an axle housing of the banjo type having an opening. a-diil'erential cage and a ring gear in the opening, a driving pinion having a supporting shaft projecting into the housing, the entire cage being oflset to one side of the shaft, a diflerential carrier secured to the axle housing and hav ing a pedestal projecting into the axle housing beyond the adjacent end of the cage, a bearing supported by the pedestal to support the adjacent end of the cage and arranged at the same side of the projecting shaft as the diiierential cage, the carrier having another portion projecting within the axle housing to form a bearing support for the projecting end oi the shaft, said bearing support being beyond the end of the cage and its supporting bearing; substantiaily as described.

15. In awaratus of the character described, an axle housing of the banjo type having an opening, a diflerential cage' and a ring gear in the opening, a driving pinion having a supporting shaft projecting rearwandiy beyond the pinion into the axle housing and arranged below axle level, the entire cage being oifset to one side of the shaft, a differential carrier secured to the axle housing and having a pedestal projecting into the axle housing beyond the adjacent end of the cage, a bearing supported by the pedestal o upport the adjacent end of the'cage, the

40 can-ier also having a projection to provide a bearing support for the projecting end of the pinion shaft, said projection being beyond the end of the cage supporting bearing and connected to the pedestal and the carrier; substantially as described.

-16. In apparatus of the character described, an axle housing of the banjo type having an opening, a diiferential cage and a ring gear in the opening, a driving pinion having a supporting shalt projecting rearwardly beyond the pinion and into the axlehousing. the entire cage being oifset to one side of the shaft, a diflerential carrier secured to the axle housing and having a pedestal projecting into the axle housing-beyond the adjacent end of the cage, a bearing supported by the pedestal to support the adjacent end of the cage and arranged substantially in the plane of the ring gear, the carrier also having a Projection to provide a bearing support for the projecting end of the shaft, said projection being beyond the end of the cage supporting bearing and connected 'to the pedestal and the carrier; substantially as described.

17. In apparatus oi. the chara'cter described, an

axle housing, a diiferential cage having a ring gear, a driving pinion having a supporting shaft projectingrearwardly into the axle housing, the shaft and the pinion being below axle level, a diflerential carrier secured to the axle housing and having a cage supporting pedestal projecting into the axle housing, the pedestal being connected to the carrier at a point above and on the,

diiferential side of the pinion shaft, the pedestal extending from the carrier substantially radially of the axle housing, a bearing support for the projecting end of the pinion shaft, said support having a portion projecting from the carrier into the axle housing beyond the projecting pedestal and connected to said pedestal for mutuai bracing; substantially as described.

A'I'I'IIJO R. SPICACCI. 

